This invention relates to an improved harvesting platform having a flexible cutter bar assembly, such as is used on a combine or the like.
Cutter bar type platforms are conventionally carried at the front of self-propelled harvesting machines, such as combines, and are transversely elongated relative to the direction of travel. The platforms are also conventionally vertically adjustable, and, when the platform is being used to harvest such crops as soybeans or the like, the platform is operated as close to the ground as possible. Such platforms conventionally include a floor with a transverse cutter bar along the leading edge of the floor. A reel is also normally provided above the cutter bar and moves the crop toward the cutter bar as the machine advances, the crop severed by the cutter bar being fed to a transverse auger which converges the crop along the floor toward the center of the platform floor for rearward discharge.
The platform floor is normally rigid; although, it is known to provide a flexible cutter bar assembly, which is free to flex in a vertical direction so that the cutter bar assembly is free to follow the contour of the ground. It is further known to mount the flexible cutter bar assembly on the platform frame by means of a number of transversely spaced fore and aft extending arms which are free to swing vertically to allow independent vertical adjustment of the different areas of the cutter bar. It is also known to provide spring means operative between the platform frame and the cutter bar assembly to partially counterbalance the weight of the cutter bar assembly to reduce the weight of the cutter bar assembly supported on the ground.
The cutter bar assembly conventionally includes a reciprocating sickle driven by a drive mechanism on one side of the platform that converts rotary motion to the reciprocating motion required by the sickle. One of the problems associated with the use of such cutter bars, of course, is the driving connection between the drive mechanism, which is normally rigid with the platform frame, and the sickle, which is free to flex in a vertical direction.